Digital Commons Network^™

Light Dynamics In The Damariscotta River Estuary With Implications For Microphytobenthos, Teiga C. Martin

Honors College

Predicting benthic light fields in the Damariscotta River Estuary (DRE) allows us to evaluate optimal microphytobenthos habitat, and determine the most the productive regions of the DRE. A model was created using instantaneous photosynthetically active radiation (PAR) to predict the spatial distribution of sufficient light fields for primary production along the benthos of the estuary. PAR was collected at six stations oriented N- S along the DRE during late September in 2016 and 2017. Calculated at each station was Z1%, experimental and model diffuse coefficients of light (Kd), and the optimal light level depth for microphytobenthos production. Light fields were …

Art And Science: A Case Study Of Their Interconnectedness In The Marine Natural Sciences, Julia Mackin-Mclaughlin

Honors College

Science and art are interrelated in the form of scientific illustration: the act of observing a subject and translating the gained knowledge into a visual form. Humans have found inspiration from the natural world since our beginnings, but the practice of accurately portraying it arose with the growing interest in natural science in the 15th century. This paper explores three questions: what is scientific illustration, what is its role in scientific research, and how has it changed through history? Modern scientific illustration thrives as an effective method to teach the general public environmental issues. I present a case study using …

A Summary Of Landings, Legislative Actions, And Possible Climate-Induced Distribution Shifts In New England Fisheries, Dylan Trueblood

Honors College

New England’s fisheries produce millions of dollars annually, and monitoring and protecting these fisheries ensures the region’s prosperity. There is evidence that the distributional centers of many fish species are shifting north so they remain within their optimal thermal range. Twenty species in New England’s fisheries have been identified as being vulnerable to climate change and, for each of these species, landings data from New England and the Mid-Atlantic were analyzed for the years 1976 – 2015. Trends in landings data were compared to trends in temperature anomaly data. Major legislative events that may have impacted landings data, e.g., fishery …

A Recommendation For Polyculture Agriculture To Reduce Nitrogen Loading That Leads To Hypoxia, Bethany Stevens

Honors College

The natural cycle of nitrogen is an essential part of both plant growth and crop

production, but in recent years there has been an increase in nitrogen through the use of synthetic fertilizers. Agricultural surface runoff can carry away the converted, mobile nitrate nitrogen into downstream systems leading to an unnatural influx of nitrogen. This increased nutrient load can stimulate algal growth in the marine ecosystem which can cause an oxygen depletion. When the dissolved oxygen levels fall, the area is deemed ‘hypoxic’ and can no longer support most aquatic life. In recent decades, industrial agriculture has used monoculture practices, …

Identifying Genes Essential For Lysogeny In Cluster E Mycobacteriophage Ukulele, Robert Levi Soohey

Honors College

Mycobacteriophage are viruses that infect Mycobacterium, including nonpathogenic M. smegmatis and pathogenic M. tuberculosis (1). Their genomes are diverse and the majority of their genes have no known function (1). Mycobacteriophage Ukulele was isolated from soil in Old Orchard Beach, Maine. Ukulele is temperate, carrying out both lysogenic and lytic lifestyles (8). Temperate phage typically encode integrase, excise, and repressor proteins, which regulate the change from lysogenic to lytic growth (10). Ukulele gp49 has been identified as the integrase but repressor and excise proteins have not been identified (8). Ukulele gp52 was previously proposed as a candidate repressor, predicted to …

Implications Of Body Size And Habitat Distribution Of Carcinus Maenas For Predation On Mytilus Edulis In The Gulf Of Maine, Mckenzie Thompson

Honors College

The blue mussel, Mytilus edulis, is a commercially important species along the Gulf of Maine. Its rapid decline in population size over the last forty years has led many researchers to question if the invasive green crab, Carcinus maenas, is affecting its distribution. The increase in annual mean water temperature, due to global climate change, has led many to fear an expansion of the green crab’s range and an increase in population density among areas they currently inhabit. The Damariscotta River in Walpole, Maine offers a unique thermal gradient to study the effects of temperature on green crab distribution, abundance, …

The Potential Impact Of Climate Change On Blue Whale Migration In The Eastern Pacific, Amanda Shuman

Honors College

Climate change is one of the most pressing problems the world is facing today. Due to human emissions, the amount of greenhouse gasses in the atmosphere is escalating at a concerning rate. This increase is causing ocean temperatures to rise, pH levels to lower, and altering the habitats of countless species. Balaenoptera musculus, or the blue whale, is a highly migratory species that relies on the stability of its’ habitats for foraging and calving grounds. They rely on the upwelling of nutrients and consistent conditions that allow for substantial prey populations to accumulate. With the effects of climate change altering …

The Effects Of Dioxin Exposure On The Hepatic Development Of Larval Shortnose Sturgeon (Acipenser Brevirostrum), Kelsey Moon

Honors College

Exposure to environmental pollutants is considered to be detrimental to the larval development of various fish species. The liver is thought to be a target organ for many chemicals because of its high lipid content which bioaccumulates lipophilic contaminants. Common impacts of dioxins found in fish livers include lipidosis and glycogen depletion. However, very few studies have been conducted to show these developmental issues in the early stages of long-lived species such as sturgeon. Given their bottom dwelling nature, sturgeon are more vulnerable to environmental pollutants such as dioxin which have long half-lives in aquatic sediments. This study sought to …

Pathobiology Of Water Molds In Fish: An Insight Into Saprolegniasis, Kathryn Liberman

Honors College

Saprolegnia is an aquatic pathogen with a fishy appetite—it develops on farmed and wild fish populations as a notoriously destructive ‘water mold’. The etiologic agent of Saprolegniasis, Saprolegnia is an opportunistic oomycete that is of significant interest in the aquaculture industry due to its financial impact and widespread effect. Previously, infection models studying the effects of Saprolegnia utilized methods that were injurious to fish and did not mimic a natural outbreak, thus making it difficult to use to evaluate new treatments for the disease. By developing a novel zebrafish (D. rerio) egg infection model, a new insight into the pathogenesis …

Ecosystem Metabolism Modeling Of Estuaries In Maine: Using Dissolved Oxygen As A Tool For Aquaculture Site Assessment, Katherine Miller

Honors College

The net primary productivity (NPP), also known as the net ecosystem metabolism, of an estuary is a value indicative of the growth and activity of an estuary’s primary producers, relative to the metabolic activity of its consumers. When NPP is high, estuaries exhibit autotrophic conditions that have the capacity to support fruitful bivalve aquaculture. For oyster farmers, the ability to monitor an estuary’s NPP would allow them to predict and prepare for seasonal changes to oyster growth that result from changes to their phytoplankton food source and access to dissolved oxygen (DO). Not only would this aid farmers on site …